﻿using System;
using System.Linq;
using System.Text;
using Xpedite.Resources.Definitions;
using Xpedite.Localization;

/* Copyright (c) 2010 CBaxter
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
 * IN THE SOFTWARE. 
 */

namespace Xpedite.Resources.Combiners
{
  internal class SpriteCssCombiner : SpriteCombinerBase
  {
    protected override ResourceType GetResourceType(IResourceDefinition definition)
    {
      return ResourceType.Css;
    }

    protected override IResource BuildResource(IResourceUrl virtualUrl, IResourceDefinition definition, ISpriteLayout spriteLayout)
    {
      if (!definition.Resources.Select(item => item.Resource).OfType<IImageResource>().Any())
        throw new XpediteException(String.Format(ExceptionMessages.AtLeastOneResourceRequired, definition.ReferenceName));

      return new Resource
      {
        Bytes = GenerateSpriteCss(spriteLayout, virtualUrl),
        Compressable = true,
        Type = ResourceType.Css,
        Encoding = Encoding.UTF8,
        LastModified = definition.Resources.Select(item => item.Resource).OfType<IImageResource>().Min(resource => resource.LastModified)
      };
    }

    private static Byte[] GenerateSpriteCss(ISpriteLayout layout, IResourceUrl virtualUrl)
    {
      StringBuilder sb = new StringBuilder();

      sb.AppendFormat(".{0}{{margin:0;padding:0,border:0 solid transparent;background-image:url('{1}');}}", layout.Name, virtualUrl.VirtualPath);

      foreach (var item in layout.Images)
        sb.AppendFormat(".{0}.{1}{{background-position:{2} {3};}}", layout.Name, item.Name, item.Position.X == 0 ? "0" : "-" + item.Position.X + "px", item.Position.Y == 0 ? "0" : "-" + item.Position.Y + "px");

      return Encoding.UTF8.GetBytes(sb.ToString());
    }
  }
}
